1. Technical Field
The invention relates to a molding made from a foam plastic having an integrated covering, and the production thereof by forming a covering material web with subsequent foaming.
The invention thus relates to actual articles, such as foam-molded mattresses and cushions for furniture and vehicles, in particular car and aircraft seats.
The term "molding made from a foam plastic" is taken to mean an article molded from a compacted foam of a synthetic polymer.
The term "integrated covering" is taken to mean a covering bonded to the foam plastic over its entire surface, as produced in foam molding, i.e., without addition of a binder and without hot-melt bonding of two prefabricated solid articles.
The term "forming" is taken to mean the deformation of a covering material web under the influence of external forces and possible heat in a mold.
"Foaming" preferably starts from liquid starting materials for the preparation of polyurethane. The foamable mixture is introduced into the formed covering. Even during production, the plastic being generated is converted into the cell structure (foam and bonded to the covering.
2. Description of the Related Art
Moldings made from a foam plastic having an integrated covering are known.
DE-A 22 27 143 discloses seat cushions made from a foam plastic which have an extensible textile cover with a sealing layer of an elastomer, the foam plastic being produced in situ by a cold-foaming recipe. The sealing layer preferably comprises a thermoplastic polyurethane elastomer or a layer of a plasticized polyvinyl chloride provided with, for example, a polyurethane solution coating on the side facing the foam (see page 4, paragraph 2, and page 5, final paragraph). In addition, a soft polyurethane foam film may be arranged between the textile cover and the sealing layer comprising a film. A laminate of this type is shaped by means of a vacuum. The cavity produced is then foamed.
The journal "Gummi-Asbest-Kunststoffe", No. 10, 1972, on pages 923 to 926, describes foam plastic moldings of the generic type, produced by forming and back foaming textile sheet-like structures sealed to polyurethane and polyvinyl chloride.
DE-C 35 06 230 describes seats and seat back cushions produced by vacuum forming and back foaming an air-permeable covering and an air-impermeable film, the covering and the film not being bonded to one another until during the forming. The film should be extensible and bondable (see column 2, lines 56 and 57); the polymer it comprises is not stated.
GB-A 2,006,667 describes the production of coverings for cushions, for example for car seats, chairs, furniture and beds. The coverings are laminates having a textile layer, a plastic foam layer and possibly a thermoplastic film. The latter can be produced from polyvinyl chloride, polyethylene or polyurethane (see page 3, lines 11-15). The laminate is mechanically formed (see claim 1, page 2, lines 26-28), preferably at from 150.degree. to 220.degree. C. It can then either be combined with the separately produced foam plastic or back foamed (see page 2, lines 8-13).
The known moldings do not always satisfy demands on the service properties; in particular their shrinkage is considerable and/or the bonding of the layers of the covering to one another and to the foam plastic is unsatisfactory.